The functional role of peptide-solvent and peptide-lipid complexes will be investigated. Initially, the molecular details and conformational consequences for formation of complexes, both in aqueous solutions and lipid bilayers, will be characterized through application of infrared, circular dichroism, and nuclear magnetic resonance spectroscopy. The initial results will be used to formulate potential energy functions to account for interactions in the molecular complexes. The experimental and theoretical techniques will be developed so that progressively more complex molecules will be amenable to conformational analysis. It is anticipated that structural studies of peptide hormones, antibiotics and transport agents will aid in understanding their functions, so that the design of therapeutic agents can proceed on a rational basis.